In treating certain medical conditions, the effective delivery of therapeutic agents to a target tissue may be prohibited by blockage. Certain tissue types with low permeability, or cell types with tight junctions, may impede the delivery of drugs to the target tissue. For example, the treatment of various eye conditions such as macular degeneration, macular edema, and central serous retinopathy often requires delivery of medication to the retina or subretinal space of a patient's eye. However, the Retinal Pigment Epithelium (RPE) of the eye can interfere with such delivery of medication. The RPE is the pigmented cell layer outside the retina and is attached to the underlying choroid and overlying retinal visual cells. The RPE acts as a barrier to the transport of molecules into the retina and subretinal space. The RPE allows small molecules, such as amino acids, to pass therethrough while preventing the passage of larger molecules such as blood borne substances provided by the choroid. Thus, it is difficult to deliver large molecule therapeutic agents intravenously or through the surrounding orbital and ocular tissue to the retina or subretinal space.